In some ways the British market had the same problem after WWI. Lots of used doubles, tens of thousands of dead young men, who never would buy doubles for three or four decades of expected life, or use a double in the family. So large numbers of doubles either sat in a closet or just got sold off as there was nobody to use them. Too much supply and almost no demand.
In the UK, alot of guns definitely moved onto the second hand market as a result of the war, when a large portion of that generation's middle and upper classes didn't come home from the war. That's one reason some makers pushed guns that were unlike those for sale before the war: Churchill's XXV and, somewhat later, the 2" 12ga being a couple examples. And it seems that there was a general shift to slightly shorter barrels in general: 28" vs 30".
Skeet did give target shooting a pretty fair shot in the arm between the wars here in the States. And all the sxs makers turned out purpose-built skeet guns. I'll have to check the poster in the men's room at one club where I shoot, but Winchester was bragging about what was then the long run in skeet--set by a chap shooting a Model 21.
